Earth-working and excavating machines, such as wheel loaders, cable shovels, drag lines, electric rope shovels (ERS), excavators, and front shovels, include implements generally used for digging into, ripping, or otherwise moving earth, rocks, debris, or other materials. Such implements commonly are various types of buckets having shapes and dimensions dependent on the type of bucket and size of the machine employing a particular bucket. These implements are subjected to abrasion and impacts that cause them to wear. To prolong the useful life of these implements, various shrouds, or wear members, can be connected to the earth-working and excavating implements at areas which experience wear. These wear members may be connected to the implements using a retention system that permits replacement of the wear members when they become worn to the extent that they should be replaced.
Some implements which have been provided with wear members have required that one or more components be welded to the implement in order to permit retention of the wear member in place on the implement. Other implements have employed various multi-component retaining systems wherein one or more of the components must be hammered in place to hold a wear member in position on an implement. The use of welded components that may need frequent replacement themselves due to extreme conditions of wear may be problematic, particularly where maintenance must be done at a work site. The use of retaining systems that are required to be hammered in place also may be problematic and difficult to put in place and remove. A shroud/wear member retaining system that is both weldless and hammerless, that is to say, one that does not require retention parts to be welded to the implement and does not require retention parts that must be hammered in place, would be both beneficial and desirable.
One retaining arrangement for a wear member is disclosed in U.S. Pat. No. 8,943,718 to Ruvang that issued on Feb. 3, 2015 (“the '718 patent”). Specifically, the '718 patent discloses an attachment system that includes a component that the '718 patent characterizes as a retainer, the retainer being welded or otherwise fastened by bolts, rivets, etc., to an implement lip. The wear member of the '718 patent is placed over the implement lip, and a locking device with a threaded opening is inserted through an aperture in the wear member. A fastener is threaded through the threaded opening of the locking device and against a plate. A biasing member acts between the retainer and the plate, which in turn biases the locking device against a rear edge of the aperture in the wear member via the fastener. The '718 patent discloses that the locking device retains the wear member on the lip of the implement, and the biasing member biases the wear member toward the lip of the implement.
Although acceptable for some applications, the wear member retaining arrangement of the '718 patent may not have broad applicability. In particular, the wear member retaining arrangement of the '718 patent may not be sufficiently robust to endure the extreme conditions of use in large, heavy-duty machines. In addition, the system disclosed in the '718 patent is specialized for use with the welded-on, or otherwise secured, retainers on the implement lip. Furthermore, both the locking device and the fastener appear susceptible to abrasion and wear during use of the implement. Such abrasion and wear of the locking device and/or fastener may cause difficulty in removing a worn wear member and installing a new wear member.
The disclosed wear member retention system is directed to overcoming one or more of the problems set forth above.